Method of making articles of cobaltchromium-tungsten alloys



' w. A. WISSLER Filed Aug. 3, 1934 INVENTORI Iv I WILLIAM A.WISSLER B ATTORNEY METHOD OF MAKING ARTICLES 0F COBALT-CHROMIUM-TUNGSTEN ALLOYS Mal ch I6, 1937'.

Patented Mar. 16, 1937 UNITED STATE METHOD OF MAKING ARTICLES OF COBALT- CHROMIUM-TUNGSTEN ALLOYS William A. Wissler, Flushing, N. Y., assignor, by mesne assignments, to Union Carbide and Carbon Corporation, a corporation of New York Application August 3,

3 Claims.

Alloys of the cobalt-chromium-tungsten type described in U. S. Patent 1,057,423 issued to Elwood Haynes, and more recent modifications thereof, are extensively used for articles designed 5 to resist wear, abrasion, or corrosion. Such alloys are practically unmachinable and articles made therefrom must be finished to size by grinding.

. It is diflicult and often impossible by ordinary methods to make threaded holes or holes of odd l0 shapes such as squares, tapers, or special dies.

in articles composed of these alloys.

The present invention has for its object a method of making articles composed at least in part of acid-resistant, diflicultly machinable alloy of the cobalt-chromium-tungsten' type, the alloy part of the article having one or more shaped holes.

The method of the invention comprises depositing the desired alloy of the cobalt-chromiumtungsten type by welding methods upon an acidsoluble metal core which is preformed to the desired size and shape of the hole. Subsequently, the metal piece is dissolved, leaving the desired hole.

' metal core is not fused to any substantial depth and that. the interalloying between the core and the deposited alloy is only slight. It is also essential that the core be of such a nature that the 0 molten cobalt-chromium-tungsten alloy will wet it and flow on smoothly. These conditions may be fulfilled by using a steel core and by welding with a reducing oxyacetylene flame. Fused borax is a particularly efiective flux.

The deposited cobalt-chromium-tungsten alloy may be built up by welding or casting the same or a different metal onto .the deposit so as to impart to the article the desired size and shape.

The process of the invention is illustrated pic- 40 torially in the accompanying drawing, Figures 1, 2, 3,'and 4.

As shown in Figure 1', an acid-soluble metal piece I0, preformed to the shape and dimensions of the desired hole, is positioned for welding, for

instance in a vise I I, and cobalt-chromium-tung- The welding procedure should be such that the.

1934, Serial No. 738,213

sten type alloy 13 is deposited on the said piece 10 from a welding rod l2 by fusion of the rod I2 with a heat-source, for example a welding torch The metal piece l0 coated with alloy l3, may then be positioned, as shown in Figure 2, within a mold 20, and molten cobalt-chromium-tungsten metal 2| may be poured from a suitable container 22 into the mold 20 around the alloy l3. When the contents of the mold 20 have cooled, a solid, cored article, as shown in Figure 3, results. If the cored article is now placed in acid, the acidsoluble core I0 is removed by the acid and the acid-resistant cobalt-chromium-tungsten alloy body 2| remains, resulting in the desired object as shown in Figure 4.

I claim:

1. Method of making articles composed at least in part of acid-resistant, unmachinable cobaltduring the welding operation, and thereafter dissolving said metal core.

3. Method of making articles composed at least in part of acid-resistant, unmachinable cobaltchromium-tungsten type alloy and provided in said part with one or more shaped holes, which comprises depositing said alloy by reducing-flame oxyacetylene welding methods upon an acid-soluble metal core preformed to the desired shape of the hole, and thereafter dissolving said metal core in said acid.

' WILLIAM A. WISSLER.

chromium-tungsten type alloy and provided in 

